GEOG 1 Lecture Notes - Lecture 26: Landform, Subduction, Seafloor Spreading
Document Summary
Earthquakes can be triggered by human activities. Flooding a valley behind a dam may induce earthquakes. Weight of the water loads the underlying crust and can create or extend fractures. These effects may produce new faults or reactive existing ones. Injecting liquid waste deep into the ground. The injection of fluids into the crust could trigger earthquakes. Increased fluid pressures and can cause slippage of numerous fractures in the host rocks. Many earthquakes of less then 4m have occurred in areas of oil and gas production in western alberta and northeast bc. Technique used to enhance hydrocarbon production by releasing natural gas or petroleum form a subsurface rock layer. Involves injecting a highly pressurized fluid into hydrocarbon-bearing rocks to create or propagate fractures. Fluid contains grains of sand or ceramics that prevent the fractures from closing when the injection is stopped and the pressure of the injected fluid is reduced.
